Due to limitations of working conditions, vibration and noise of construction machinery are difficult to be eliminated. In the conventional technology, vibration damping is achieved generally by providing a damping mechanism and optimizing the structure of the damping mechanism, thus the design of damping mechanism has always been a key issue of the structural design of construction machineries such as a bulldozer.
Vibration of the bulldozer mainly arises from five aspects including a power system, a traveling system (road condition), a vehicle body structure, a hydraulic system and a cooling fan system. In the above five aspects, vibration caused in the acting of the engine in the power system is a main vibration source of the bulldozer, and, the vibration of a bulldozer with a power system using a diesel engine is more serious than a bulldozer with a power system using a gasoline engine. Hence, it is required to improve damping measures for components which are directly connected to the engine or indirectly connected to the engine via pipelines. Components directly connected to the engine mainly include a traveling hydraulic pump, a working hydraulic pump, and relevant gas pipes and oil pipes; and components connected to the engine via pipelines or the like mainly include an air cleaner, an exhaust after-treatment device or the like.
Currently, each of parts of the bulldozer in the conventional technology generally adopts a respective damping mechanism, for example, the air filtering device and the exhaust after-treatment device are fixed to the engine via respective damping components, and the damping components are used to reduce the adverse effects caused by vibration of the engine on the air filtering device or the like. However, this vibration decreasing effect is not satisfactory, and this arrangement increases the length of an exhaust pipeline, which in turn increases the resistance for discharging exhaust.
The traveling hydraulic pump and the working pump are arranged on a flywheel housing at a rear end of the engine, and dampers are arranged between the engine and the traveling hydraulic pump as well as between the engine and the working pump, the engine drives directly the hydraulic pump to work via the dampers, and the vibration of the engine is reduced by the dampers.
In addition, the vehicle body structure is formed by a mass of sheet-type parts by welding, this structure is apt to generate a new vibration source under the driving of the power system and the traveling system, damping of the engine and the hydraulic pump is performed independently, and the vibrations of the engine and the hydraulic pump are asynchronous, and especially when an intrinsic frequency and a vibration frequency of the engine are identical, resonance phenomena may occur, which not only is disadvantageous to the driving of the bulldozer, but also reduces the service life of the bulldozer greatly.
Therefore, an urgent technical issue to be addressed by the person skilled in the art is to optimize the structure of the bulldozer in the conventional technology, to effectively reduce adverse effects of vibration on various components and improve the service life and working performance of the components.